Apparatus for producing a heterogeneous diffusion of fibers



July 3, 1962 J. H. GOLDMAN APPARATUS FOR PRODUCING A HETEROGENEOUSDIFFUSION OF FIBERS 2 Sheets-Sheet 1 Filed May 19, 1958 INVENTOR.

JOSHUA H. GOLDMAN ATTORNEY July 3, 1962 J. H. GOLDMAN 3,041,676

APPARATUS FOR PRODUCING A HETEROGENEOUS DIFFUSION OF FIBERS Filed May19, 1958 2 Sheets-Sheet 2 INVENTOR. JOSHUA H. GOLDMAN ATTOR N E? UniteStates Patent M 3,641 676 APPARATUS FOR PRODIICING A I-IETEROGENE- OUSDIFFUSIQN 0F FIBERS Joshua H. Goldman, Box 14, Hadlyme, Conn. Filed May19, 1958, Ser. No. 736,339

8 (Iiaims. (Cl. 19-155) My present invention relates to the distributionof fibers and more particularly to a novel apparatus for producing aheterogeneous diffusion of fibers.

This application is a continuation in part of my copending applicationSerial No. 335,376, filed February 5, 1953, issued July 1, 1958, PatentNo. 2,841,204.

The principal object of the present invention is to provide an apparatusfor distributing fibers in a heterogeneous non-parallel and non-orientedrelation.

Another object of the present invention is to provide an apparatus forforming a thin fibrous web having tensile strength longitudinally andtransversely in the plane of the web as well as at right angles to theplane of the web. A further object of the present invention is toprovide an apparatus which produces a centrifugal force on high speedrolls to throw the fibers and form a chaotically'disposed mass offibers.

Another object of the present invention is to provide an apparatus forforming a non-woven fibrousweband for impregnating or coating the web orboth.

With the above and other objects and advantageous features in view, myinvention consists of a novel arrangement of parts, more fullydisclosed'in the detailed description following, in conjunction with theaccompanying drawings, and more particularly defined in the appendedclaims.

In the drawings, 7

FIG. 1 is a longitudinal section, partly diagrammatic, of an apparatusembodying my invention.

FIG. 2 is a view similar to FIG. 1 of the coating device.

FIG. 3 is a view similar to FIG. 1 of the impregnation device.

It has been found desirable to provide a fibrous material in anextremely thin non-woven web composed of intertwined fibers. Such a webhas many uses both in industry and in medicine. In my United StatesPatents No. 2,039,312, entitled Reinforced Carded Webs, I have shown amethod which will produce a web having considerable tensile strengthlongitudinally in the plane of the web. However, it will be found thatthe web separates quiteeasily transversely to the plane of'the web. Inmy copending application hereinabove refer'redto I have described anovel method of producing a fibrous web having considerable tensilestrength both longitudinally and transversely in the plane of the web.

The present invention describes a machine for carrying out this novelmethod. The machine of the present invention comprises a series ofrotating rolls designed to segregate, attenuate and disburse the fibersand a con.- denser on which the web is formed. Provision is also madefor coating or impregnating the web or both. The desired web can be madeof any fibrous material, either natural or artificial, or blendsthereof. The principal portion of the apparatus of the present inventioncomprises a plurality of high speed rolls which attenuate and throw thefibers by centrifugal force. Thereafter the fibers may be condensed onany desiredsur-face and in any desired manner. In the illustrated form,the web is formed by condensing the fibers on condensing rolls.

In a conventional card the rolls are so arranged and the speed soregulated that the function of the card to clean and align the fibers isrealized. The function of the present invention is to disperse thefibers by subjecting Patented July 3, 1962 them to sufiicientcentrifugal force to enable them to be thrown in a chaotic pattern on toa condensing surface.

FIG. 1 shows a preferred arrangement of rolls designed to accomplish thedesired purpose. The fibers 10 may be in the form of picker lap, sliveror cut staple. The fibers are fed along a plate 11 having an integralvertical portion 12 which tapers to a sharp edge and extends between therolls 13 and 14. The roll 13 is mounted just above the plate 11 andconstitutes the feed roll. The roll 13 is provided with pins or metallicclothing 15 in the conventional manner. The feed roll 13 serves to feeda predetermined quantity of fibers to the chelater roll 14 which is alsoprovided with a toothed surface 16. The feed roll 13 rotatescounterclockwise and the chelater roll 14 also rotates counterclockwise.The spacing between the feed.

and chelater rolls is .005" to .010". The pins 15 on the 1 chelater roll14 present a uniform film of unintentionally aligned fibers which theroll 17 attenuates and separates. The distributor roll 17 also rotatescounterclockwise at a maximum clearance of .002 from the roll 14. Aplate 18 is positioned between the rolls 14 and 17 and is provided witha tapered edge extending sharply between the rolls. Here again thefibers are removed from the surface of the roll 14 by the roll 17 acrossthe edge of the plate 18. The surface of the roll 17 may be similar tothat of the rolls 13 and 14, having pins or metallic clothing, or thesurface may be merely roughened with engraved flutes or fine thread.

Applicant has found that the operation of the device of the presentinvention is practically self-cleaning. The fibers on the sinface of theroll 14 will be transferred to the roll 17 cleanly. However, certaintypes of fibers may have a tendency to resist transfer and a few fibersmay be left on the roll. To prevent a build up of untransferred fibers aclearing roll 19 may be used as shown in FIG. 1. The roll 19 is providedwith metallic clothing 20 on its outer surface and straddles the rolls14 and 17 with a clearance of approximately .005". This roll rotatesclockwise and will clear the fibers from the roll 14 to the roll 17.

Adjacent the roll 17 is a diffusion roll 21 rotating clockwise. Theclearance between the surfaces of the rolls 17 and 21 should be nogreater than .0005". The surface of the roll 21 may be identical withtheroll 17. The roll 21 removes the fibers from the surface of the roll 17and throws them by centrifugal force in a defined path through the duct22 on to the condensing rolls 23 and 24. The condensing rolls 23 and 24are positioned one over the other as illustrated in FIG. 1, the upperroll 23 rotating counterclockwise and the lower roll 24 rotatingclockwise. The surface of the condensing rolls are foraminous and theirspeed of rotation determines the density of the web 25 formed thereon.

A metallic shield 26 extends around all the rolls except the feed roll13 and, of course, the condensing rolls 23 and 24. The shield 26 ispositioned not more than .020" from the surface of the rolls and theinside surface of the shield 26 is ground and polished. At the upperportion of the roll 17, adjacent the clearing roll 19, the shield 26 isprovided with a small gap 27 for bleeding off any excess entrapped air.\I

The size and speed of the feed roll 13 is not critical. Thediameter-length ratio must be great enough to resist bending and thespeed is governed by the quantity of stock bedded in the teeth. Thediameter and the revolutions per minute of the roll 14 are thereforecritical. I have found that a diameter of six inches and speed of 900rpm. is a minimum for satisfactory performance.

The surface speed of the distributor roll 17 should be not less thantwice that of the roll 14 in order that the fiber stock be furtheropened and attenuated. This roll is.

therefore illustrated as having a much greater diameter than the roll.14 to provide the indicated surface speed. As has been heretoforepointed out this roll may be provided with pins, metallic clothing ormilled or engraved grooves.

The speed and diameter of the diffusion roll 21 is the most critical.The fibers are removed from roll 17 by roll 21 whose speed must besuflicient to throw the fibers by centrifugal force which is equal tothe mass of the fibers multiplied by the square of their velocity anddivided by the radius of the roll. I have found that a speed of 2000rpm. and a diameter of six inches is a minimum for fibers of highdensity and I have used speeds of, 6000 rpm. with light fibers. Thesurface of the roll 21 is similar to that of the roll 17 and may be finemetallic or flexible clothing or, if the velocity is high, may be anetched or engraved surface. This is possible because the fibers aretransferred, conducted and thrown at the rolls 17 and 21 by the boundarylayer of air surrounding the roll rather than the roll itself. Thisboundary layer of air is held close to the rolls and restricted by theshield 26 which is concentric with the rolls. At the point of dischargethe impetus given to the fibers by the velocity of the roll 21 ismaintained by the stream of air which leaves the roll with the fibers.No extraneous air is introduced to conduct the fibers nor is anynegative pressure used to collect them on the condenser rolls.

The conveyance of fibers by air is well known to the alt. Suoh a systemhas many disadvantages residing in the fact that the airborne fiberstend to agglomerate and that the air stream moves with a laminar flowthrough the ducts. Also the fibers tend to travel in parallel relationwith the air flow. For these reasons discrete fibers cannot betransported successfully by and the system is mainly used in the processof forming picker lap.

The apparatus of the present invention is therefore designed to throwthe fibers in discrete form by centrifugal force rather than carry themby a moving mass of air. The velocity acquired by the fibers will bedirectly pro portional to their mass, their density, the force appliedand inversely proportional to the viscosity of the ambient medium. Themass of each fiber is small but the density is high particularly whenexposed to an atmosphere of high humidity. The apparatus thereforeapplies a force of a high order of magnitude. For example, using theapproximate formula:

Diameter in feei' r.1:o.1:a. 6000 and considering a six inch rollrevolving at 6000 r.p.m. we would obtain a force equal to 3000 times theforce of gravity.

When the product of the mass, density and force is divided by theviscosity an exceedingly large velocity results. This is true becausethe viscosity is nearly equal to zero due to the fact that the boundarylayer of air is moving at the same speed as the fibers so that norelative motion exists. As an example of the energy imparted, theapparatus of the present invention has propelled one inch cotton fibersa distance offifteenfeet from the surface of a five and one half inchroll rotating at 4225 rpm.

Note that surface speed controls the relation between Force in g units=the rolls 13 and 14, but is not significant with respect to fibers, thefinal roll 21 must develop a centrifugal force g in accordance with theabove described formula. This force depends on the speed-radius relationof the roll. For example, applicant has constructed a roll 3" indiameter rotating at 10,000 rpm. This develops a force of more than 4000gs.

The fibers leave the surface of the roll 21 in a well definedtrajectory. To prevent turbulence the inner surfaces of the duct 22 mustbe smooth and designed to conform to the path of the fibers. The duct 22should be approximately eight times the diameter of the roll 21 inlength. The curvature of the upper and lower walls may be plotted bystandard formulae.

The condenser rolls 23 and 24 collect the fibers which leave the roll inthe form of a web 25 which comprises a heterogeneous mass ofnon-parallel fibers. The web 25 can of course be used in this form formany purposes such as filtering, as an absorbent, etc. However, suchwebs are in many cases either impregnated or coated or both. FIGS. 2.and 3 are schematic views of arrangements for impregnating and coating.Since the apparatus distributes the fibers in a heterogeneous mass, theycan be condensed on any surface requiring reinforcement with suchfibers. For example, in manufacturing plastic fiberglass tubing, theplastic tubing can be used as the condensing surface and glass fibersmay be thrown by the device on to the plastic tubing. Similarly otherfibers can be thrown on irregular surfaces such as suit cases, autobodies, etc.

FIG. 2 illustrates one formof coating device. The web 25 may be feddirectly from the web-forming apparatus shown in FIG. 1 or theimpregating arrangement shown in FIG. 3. It may be passed around a feedroll 28 over a large roll 29 rotating clockwise. Disposed above andslightly to one side of the roll 29 is the transfer roll 30 whichactually lays the coating on the web 25. Note that the transfer roll 30also rotates clockwise. Excess V coating is removed from the surface ofthe roll 30 by a doctor blade 31. The reservoir of coating material 32is positioned above the transfer roll 30 and designed to provide thesurface of the roll 30 with the coating material. To make sure that noexcessive coating is provided and that the coating is uniform, ametering roll 33, rotating clockwise, abuts the roll 30. A doctor blade34 is provided to remove the coating from the metering roll 33 back intothe reservoir. With the above arrangement a coating of any desired typemay be laid on the upper surface of the web 25. Similarly a secondcoating may be laid on the other side of the Web if desired. The type ofcoating and method of drying may be varied to suit any requirements.

FIG. 3 illustrates an arrangement which can be used for impregnating theweb 25. Where the web is to be impregnated and coated it must of coursebe first impregnated. The web 25 is impregnated by passing the webbetween the rolls 35 and 36. The roll 35 may be immersed in a reservoir37 of the impregnating solution. The roll 35 rotates clockwise and theroll 36 rotates counterclockwise. A triangular dam 38 is provided ateach end between the rolls 35 and 36 for preventing excessive amounts ofsolution from overflowing. The impregnated web passes around the roll 36which rotates counterclockwise and through a drying area utilizing adrying apparatus 39 which may be of any desired type, such as heat,infra-red light, etc. The impregnated web 25 may then be passed througha series of calender rolls 40.

The size and width of the individual rolls can of course be varied tosuit different requirements within the limitations imposed bydiameter-length relation to prevent bending or whipping. It is onlynecessary that the comparative speeds between rolls and the minimumspeeds herein indicated be maintained. At these extremely high speedsthe roll should be well. balanced and preferably individually driven forbetter control. It will be noted that roll 17 is approximately twice thediameter of the roll 14 and has an indicated surface speed of approxi-'I the rolls and the shield without the rough physical contact in aconventional card. As a result the present apparatus will handle fibers,such as glass fibers, which are extremely brittle and normallyimpossible to card or separate without pulverizing. The apparatus of thepresent invention therefore produces a disruption of the parallelism ofthe fibers to form a non-woven heterogeneous mass of non-parallel fibersevenly distributed and of substantially uniform Weight throughout. Whenproperly processed, the resultant web can be made-extremely thin,extremely light, and with a high tensile strength in every direction inthe plane of the web. The product can be made highly absorbent, as, forexample, with cotton fibers. It can also be treated to make itwaterproof. It can be dyed and it can be stiffened. The web can be usedfor insulation, for wiping cloths, and in many other applications.

The apparatus can readily be adapted to other uses. For example, theseparation of long and short fibers is a slow and costly process. InView of the formula set forth herein it is obvious that a longer fiber,having more mass will be thrown further by the apparatus than a shorterfiber. The applicant has found that the apparatus will discharge astream of fibers at high speed when the condensing rolls are removedwith the longer fibers at the far end of the trajectory and the shorterfibers closer to the apparatus. If bins are provided for the fibers tofall into, the apparatus can readily be used as a high speed separator.This effect is only possible where the fibers are propelled bycentrifugal force. Note that when fibers are propelled by a stream ofair under pressure, the heavier fibers will fall first and the lighterones will go further and this only within the confines of the apparatus.Other advantages and uses of the apparatus of the present invention willbe readily apparent to a person skilled in the art.

I claim:

1. An apparatus for distributing fibers by centrifugal force in anon-parallel non-oriented relation, comprising a rotatably mountedchelater roll, a distributor roll rotatably mounted adjacent saidchelater roll and rotating in the same direction, a diffusion rollrotatably mounted ad jacent said distributor roll and rotating in theopposite direction, said rolls rotating at progressively higher speeds,said diffusion roll imparting a centrifugal throwing force to the fiberspassing through the apparatus, and shielding extending concentricallyaround the non-adjacent surfaces of said chelater, distributor anddiffusion rolls and spaced not more than .020" therefrom.

2. An apparatus for distributing fibers by centrifugal force in anon-parallel non-oriented relation, comprising a rotatably mountedchelater roll, a distributor roll rotatably mounted adjacent saidchelater roll and rotating in the same direction, a diffusion rollrotatably mounted adjacent said disnibutor roll and rotating in theopposite direction, said rolls rotating at progressively higher speeds,said diffusion roll imparting a centrifugal throwing force to the fiberspassing through the apparatus, and shielding extending concentricallyaround the non-adjacent surfaces of said chelater, distributor anddiffusion rolls and spaced not more than .020" therefrom, said chelaterroll being covered with metallic clothing, said distributor roll havinga roughened surface and being spaced not more than .00 from saidchelater roll, said diffusion roll having 6 a roughened surface andbeing spaced not more than .0005 from said distributor roll.

3. An apparatus for distributing fibers by centrifugal force in anon-parallel non-oriented relation, comprising a rotatably mountedchelater roll, a distributor roll rotatably mounted adjacent saidchelater roll and rotating in the same direction, a diffusion rollrotatably mounted adjacent said distributor roll and rotating in theopposite direction, said rolls rotating at progressively higher speeds,said diffusion roll imparting a centriugal throwing force to the fiberspassing through the apparatus, a feed roll rotatably mounted in front ofsaid chelater roll, an L- shaped feed plate extending beneath said feedroll, the vertical leg of said plate having a wedge edge extendingbetween said feed and chelater rolls, shielding extending concentricallyaround the non-adjacent surfaces of said chelater, distributor anddiffusion rolls and spaced not more than 0.20" therefrom, said shieldingbeing internally ground and polished, a duct extending from saiddiffusion roll to receive the thrown fibers, and condenser means at theopen end of said duct to form said fibers into a non-wovenweb, saidchelater roll being covered with metallic clothing, said distributorroll having a roughened surface and being spaced not more than .002"from said chelater roll, said diffusion roll having a roughened surfaceand being spaced not more than .0005 from said distributor roll.

4. An apparatus for distributing fibers by centrifugal force in anon-parallel non-oriented relation, comprising a rotatably mountedchelater roll, a distributor roll rotat ably mounted adjacent saidchelater roll androtating in the samedirection, a Wedge-shaped plateextending upwardly between said chelater and distributor rolls, adiffusion roll rotatably mounted adjacent said distributor roll androtating in the opposite direction, said rolls rotating at progressivelyhigher speeds, said diffusion roll imparting a centrifugal throwingforce to the fibers passing through the apparatus, a feed roll rotatablymounted in front of said chelater roll, an L-shaped feed plate extendingbeneath said feed roll, the vertical leg of said plate having a wedgeedge extending between said feed and chelater rolls, and shieldingextending concentrically around the non-adjacent surfaces of saidchelater, distributor and diffusion rolls and slightly spaced therefrom,a duct extending from said diffusion roll to receive the thrown fibers,and condenser means at the open end of said duct to form said fibersinto a non-woven web, and a clearing roll rotatably mounted above saidchelater and distributor rolls and spaced .005" from each, saidshielding extending around said clearing roll, said chelater roll beingcovered with metallic clothing, said distributor roll having a roughenedsurface and being spaced not more than .00 from said chelater roll, saiddiffusion roll having a roughened surface and being spaced not more than.0005" from said distributor roll.

5. An apparatus for distributing fibers by centrifugal force in anon-parallel non-oriented relation, comprising a rotatably mountedchelater roll, a distributor'roll rotatably mounted adjacent saidchelater roll and rotating in the same direction, a diffusion rollrotatably mounted adjacent said distributor roll and rotating in theopposite I direction, said rolls rotating at progressively higherspeeds,said diffusion roll imparting a centrifugal throwing force to the fiberspassing through the apparatus, and shielding extending concentricallyaround the non-adjacent surfaces of said chelater, distributor anddiffusion rolls and spaced not more than .020" therefrom, said diffusionroll having a minimum diameter of 6" with a minimum speed of 2000 rpm.

6. An apparatus for distributing fibers by centrifugal force in anon-parallel non-oriented relation, comprising a rotatably mountedchelater roll, a distributor roll rotatably mounted adjacent saidchelater roll and rotating in the same direction, a diffusion rollrotatably mounted adjacent said distributor roll and rotating in theopposite direction, said rolls rotating at progressively higher speeds,

7 said diffusion roll imparting a centrifugal throwing force tween saidfeed and chelater rolls, shielding extending concentrically around thenon-adjacent surfaces of said chelater, distributor and dilfusion rollsand spaced not more than .020" therefrom, said shieldingbeiug'internally ground and polished, a duct extending from saiddiffusion roll to receive the thrown fibers, and condenser means at theopen end of said duct to form said fibers into a non-woven web, saiddiffusion roll having a minimum diameter of 6" with a minimum speed of2000 rpm.

7. An apparatus for distributing'fibers by centrifugal force in anon-parallel non-oriented relation, comprising a rotatably mountedchelater roll, a distributor roll rotatably mounted adjacent saidchelater roll and rotating in the same direction, a diffusion rollrotatably mounted adjacent said distributor roll and rotating in theopposite direction, said rolls rotating at progressively higher speeds,said diifusion roll imparting a centrifugal throwing force to the fiberspassing through the apparatus, and shielding extending concentricallyaround the non-adjacent surfaces of said chelater, distributor anddiffusion rolls and spaced not more than .020" therefrom, said chelaterroll being covered with metallic clothing, said distributor roll havinga roughened surface and being spaced not more than .002" from saidchelater roll, said diffusion roll having a roughened surface and beingspaced not more than .0005" from said distributor roll, said difiusionroll having a minimum diameter of 6 with a minimum speed of 2000 r.p.m.

8. An'apparatus for distributing fibers by centrifugal force in anon-parallel non-oriented relation, comprising a rotatably mountedchelater roll, a distributor roll rotatably mounted adjacent saidchelater roll and rotating in the same direction, a diffusion rollrotatably mounted adjacent said distributor roll and rotating in theopposite direction, said rolls rotating at progressively higher speeds,said diifusion roll imparting a centrifugal throwing force to the fiberspassing through the apparatus, a feed roll rotatably mounted infront ofsaid chelater roll, an L- shaped feed plate extending beneath said feedroll, the vertical leg of said plate having a wedge edge extendingbetween said feed and chelater rolls, shielding extending concentricallyaround the non-adjacent surfaces of said chelater, distributor anddiffusion rolls and spaced not more than .020 therefrom, said shieldingbeing internally ground and polished, a duct extending from saiddiffusion roll to receive the thrown fibers, and condenser means at theopen end of said duct to form said fibers into a nonwoven web, saidchelater roll being covered with metallic clothing, said distributorroll having a roughened surface and being spaced not more than .002"from said chelater roll, said dilfusion roll having a roughened surfaceand being spaced not more than .0005 from said distributor roll, saiddiifusion roll having a minimum diameter of 6" with a minimum speed of2000 r.p.m.

References Cited in the file of this patent nil.

